JPH11309816A - Liquid packaging laminate paper and liquid packaging vessel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a protection property of packaged matter such as a content of foods having a gas barrier property or the like, and facilitate disposal handling because aluminum foil can be saved, by laminating a paper-like layer, a resin-composition layer having an inorganic layer-like compound, and a thermoplastic resin layer. SOLUTION: This liquid packaging laminate paper is produced by laminating a paper-like layer 1, a resin composition layer 3 having an inorganic layer-like compound, and thermoplastic resin layer 4. A formation of each layer 1, 2, 3, i.e., the order of lamination is not limited, and other layers can be laminated between each layer 1, 2, 3. The liquid packaging laminate paper has an oxygen permeability (mL/atm.m<2> .day) of 1 or lower and, preferably, has a gas barrier property of 0.05 or less. As concrete examples of material of the paper-like layer 1, there are given craft paper, wood-free paper, glassine paper or the like, and concrete examples of the thermoplastic resin layer 4, are polyethylene, ethylene-propylene copolymer, ethylene-butene copolymer and the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated paper for liquid packaging which is suitable for preserving water-containing contents (packages) such as juice and alcohol, and which has excellent gas barrier properties against oxygen and the like. The present invention relates to a liquid packaging container.

[0002]

2. Description of the Related Art Conventionally, paper, glass, metal, and the like have been used for preservation of contents including water such as juice and liquor for a long time. In recent years, plastics have been widely used in this field. It has become.

[0003] This is because plastic has a function as a packaging material, for example, (1) has a large degree of freedom in design due to the variety of materials, (2) has good moldability, and (3) has excellent corrosion resistance. This is because it satisfies suitable functions as a packaging material, such as (4) low specific gravity and (5) low thermal conductivity.

Further, in order to improve functions such as gas barrier properties such as oxidation prevention, by bonding a plurality of material layers including plastic, the advantages of each material layer are utilized and the defects are compensated for. Film laminates have been proposed.

As such a film laminate, for example, a film laminate composed of a polyethylene layer, an aluminum foil, and a paper layer is exemplified. The film laminate is used as a container for liquid packaging, for example, in a carton container for milk or juice.

[0006]

However, in the above-mentioned conventional film laminate, the gas barrier property is improved by the aluminum foil. However, in order to impart the gas barrier property, the aluminum foil has a thickness of about 7 μm to 20 μm. A film thickness is required, which causes a problem that it takes time to dispose or recycle the film laminate having the aluminum foil. That is, in the above-mentioned film laminate, there is a problem that it takes a long time to process when the temperature becomes high at the time of incineration or the residue (ingot) increases due to the thickness of the aluminum foil.

The present invention has excellent gas barrier properties,
It is an object of the present invention to provide a laminated paper for liquid packaging which is easy to dispose or recycle and a container for liquid packaging using the same.

[0008]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above problems, and as a result, by disposing a resin composition layer containing an inorganic layered compound as a gas barrier layer,
Finding that it can be easily disposed of with gas barrier properties,
The present invention has been completed.

That is, the laminated paper for liquid packaging of the present invention comprises:
In order to solve the above problems, the present invention is characterized by comprising a paper-like material layer, a resin composition layer having an inorganic layered compound, and a thermoplastic resin layer.

[0010] According to the above structure, by having the paper-like material layer, moldability and strength for liquid packaging can be provided, and in the resin composition layer, the inorganic layered compound is formed in the shape of the layer. Because they face each other and are oriented so as to be substantially parallel to the surface direction of the resin composition layer, it is possible to impart a gas barrier property to the resin composition layer by the maze effect of the inorganic layer compound. Become.

In addition, in the above configuration, the thickness of the inorganic layered compound in the resin composition layer can be set to, for example, about 1 nm. Therefore, the thickness of the resin composition layer containing the inorganic layered compound is changed to the thickness of the resin composition layer. While maintaining gas barrier properties
The thickness can be set thinner than before, and the treatment of the resin composition layer at the time of disposal can be facilitated.

In the liquid packaging container according to the present invention, a container body for packaging an article to be packaged containing water is defined in claims 1 to 12.
, Characterized by being formed of the laminated paper for liquid packaging according to any one of the above.

According to the present invention, a laminated paper for liquid packaging and a container for liquid packaging using the same, which have gas barrier properties, are excellent in preservability of a packaged object, and are easy to dispose at the time of disposal, can be obtained. .

[0014]

FIG. 1 shows an embodiment of the present invention.
The following is a description based on FIG. 9.
As shown in FIG. 1, the laminated paper for liquid packaging of the present invention comprises a paper-like material layer 1, a resin composition layer 3 having an inorganic layered compound,
And a thermoplastic resin layer 4. In the laminated paper for liquid packaging, the layer structure of the layers 1, 3, and 4, that is, the lamination order is not particularly limited.
Another layer may be laminated between the third and fourth layers. In addition,
When the thermoplastic resin layer 4 is used as a sealant layer, the thermoplastic resin layer 4 is set as the outermost layer.

The laminated paper for liquid packaging has the resin composition layer 3 provided with the inorganic layered compound, so that the oxygen permeability (m) can be measured according to the oxygen permeability measurement method described later.
L / atm · m ² · day) is 1 or less, more preferably,
It has excellent gas barrier properties of 0.1 or less, more preferably 0.05 or less.

In the above-mentioned laminated paper for liquid packaging, further strength,
For example, in order to impart tensile strength, it is preferable to further laminate the stretched film layer 2 between, for example, the resin composition layer 3 and the thermoplastic resin layer 4, as shown in FIG.

The material of the paper-like material layer 1 of the present invention is not particularly limited as long as it has a strength capable of forming the container body in the liquid packaging container of the present invention. , Glassine paper, parchment paper, synthetic paper and various cardboards.

The thermoplastic resin layer 4 of the present invention is capable of retaining liquid contents such as juices, pasty foods and the like, and is capable of preventing water penetration and leakage and dissolving aromatic substances. What is necessary is just to have solvent resistance with respect to solvents, such as alcohol. Further, the thermoplastic resin layer 4
Preferably have heat sealing properties.

As the thermoplastic resin layer 4, for example,
Polyethylene (low density, high density), ethylene-propylene copolymer, ethylene-butene copolymer, ethylene-hexene copolymer, ethylene-octene copolymer, polypropylene, ethylene-vinyl acetate copolymer, ethylene-
Methyl methacrylate copolymer, polyolefin resin such as ionomer resin, polyethylene terephthalate, polybutylene terephthalate, polyester resin such as polyethylene naphthalate, nylon-6, nylon-6,6, meta-xylene diamine-adipic acid condensation polymer, Amide resins such as polymethyl methacrylimide, acrylic resins such as polymethyl methacrylate,
Polystyrene, styrene-acrylonitrile copolymer,
Styrene-acrylonitrile-butadiene copolymer, styrene-acrylonitrile resin such as polyacrylonitrile, hydrophobicized cellulose resin such as cellulose triacetate, cellulose diacetate, halogen such as polyvinyl chloride, polyvinylidene chloride, polyvinylidene fluoride, and Teflon Containing resin, polyvinyl alcohol, ethylene-vinyl alcohol copolymer, high hydrogen bonding resin such as cellulose derivative, polycarbonate resin, polysulfone resin,
Engineering plastic resins such as polyethersulfone resin, polyetheretherketone resin, polyphenylene oxide resin, polymethylene oxide resin, and liquid crystal resin are exemplified.

In the thermoplastic resin layer 4, a sealant having a high impact strength is preferable especially when the sealing property of the contents is required. As a resin satisfying these, polyolefin-based resins such as polyethylene and ethylene-α-olefin copolymer synthesized using a metallocene-based catalyst or a late transition metal complex catalyst are preferable. Such a sealant preferably has a density of 0.920 g / cm ³ or less.

In consideration of environmental protection at the time of disposal or recycling, a resin consisting of only carbon and hydrogen, a resin consisting of only carbon, hydrogen and oxygen, For example, a polyolefin resin is preferable. As the thermoplastic resin layer 4 as the heat seal layer of the laminated paper for liquid packaging of the present invention, for the pulp cycle,
Emulsion sealants such as ethylene-vinyl acetate copolymers and acrylic resins are preferred.

The laminated paper for liquid packaging of the present invention further comprises:
A barrier layer made of a metal or a metal oxide such as silica, alumina, or aluminum is provided between any of the layers of the film laminate, for example, between the resin composition layer 3 and the paper-like material layer 1. １０００1000 nm, preferably 10 nm〜20
It may be provided by being laminated at 0 nm. With such a barrier layer, gas barrier properties can be further ensured, and light-shielding properties can be imparted. Regarding the method of forming the barrier layer,
Although not particularly limited, a vapor deposition method and a sol-gel method can be used, and a vapor deposition method is particularly preferable.

By the way, in the conventional gas barrier container,
In order to impart gas barrier properties, a metal layer such as an aluminum foil was required at a film thickness of 7 μm to 20 μm. It took time.

However, in the present invention, by providing the above-mentioned barrier layer with a thickness of 1000 nm or less, the gas barrier properties can be further ensured and the light-shielding properties can be imparted.
And, since the above film thickness can be set thinner than before,
Disposal processing and recycling can also be facilitated.

The resin composition layer 3 of the present invention is formed by applying (coating) a coating liquid obtained by dispersing a resin composition containing a cleaved inorganic layered compound in a dispersion medium, for example, on a paper-like material layer 1. The resin composition is obtained by forming a coating film by removing the dispersion medium from the coating film by, for example, drying. At the time of coating, the resin contained in the coating liquid includes the resin used in the thermoplastic resin layer 4 described above, an ethylene-vinyl acetate copolymer emulsion, an acrylic resin emulsion, a urethane resin emulsion, and an acrylic resin.
A urethane copolymer resin emulsion can be used, but from the viewpoint of dispersibility, a highly hydrogen-bonding resin is preferable.

The above-mentioned inorganic layered compound is an inorganic compound having a layered structure in which unit crystal layers are stacked on each other, and has a particle size of 5 μm or less and an aspect ratio of 50 to 5000 in terms of gas barrier property when cleaved. Hereinafter, there is no particular limitation as long as the aspect ratio is more preferably in the range of 200 to 3000.

When the aspect ratio is less than 50, the gas barrier property is not sufficient, and when the aspect ratio is more than 5000, it is technically difficult and economically expensive. Further, when the particle size is 3 μm or less, the transparency becomes better, and when the particle size is 1 μm or less, it is more preferable for applications in which transparency is important.

Specific examples of the inorganic layered compound used in the present invention include graphite, phosphate derivative-type compounds (zirconium phosphate compounds, etc.), chalcogenides,
And clay minerals. Here, the “chalcogen compound” includes a group IV (Ti, Zr, Hf) and a group V (V,
Nb, Ta) and group VI (Mo, W) dichalcogenides represented by the formula MX ₂ (M is the above element, X is chalcogen (S, Se, Te)).

The particle size of the inorganic layered compound used in the present invention refers to a particle size obtained by a diffraction / scattering method in a dispersion medium. Although it is extremely difficult to measure the true particle size in the resin composition layer 3, it is sufficiently swelled and cleaved with a dispersion medium of the same type as the dispersion medium used in the diffraction / scattering method, and is used for the resin composition layer 3. In the case of compounding with a resin, the particle size of the unit crystal layer 31 which is a cleaved inorganic layered compound in the resin 32 in the resin composition layer 3 shown in FIG. 3 is a cleaved inorganic layered compound in a dispersion medium. This can be considered to correspond to the grain size of the unit crystal layer.

(Method for Determining Average Particle Size) Methods for determining the average particle size of particles in a liquid include a method based on a diffraction / scattering method, a method based on a dynamic light scattering method, a method based on a change in electric resistance, and a method after photographing in a liquid microscope. A method by image processing or the like is possible.

In the dynamic light scattering method, when the resin and the particles coexist, the apparent liquid viscosity is different from that of the pure dispersion medium, so it is difficult to evaluate the method. There is a problem of resolution in the method using image processing after photographing in a submerged microscope, and each method is difficult to use.

In the method based on the diffraction / scattering method, when a resin solution, for example, an aqueous resin solution, has substantially low scattering (transparency), and therefore scattering due to particles is dominant, the method does not depend on the presence or absence of the resin. This is preferable because information on only the particle size distribution of the particles can be obtained.

(Measurement of Average Particle Size by Diffraction / Scattering Method) The particle size distribution and average particle size measurement by the diffraction / scattering method are carried out by irradiating a dispersion obtained by dispersing a swollen and cleaved inorganic layered compound in an aqueous dispersion medium. The diffraction / scattering pattern obtained when the light is allowed to pass through is calculated by using the Mie scattering theory or the like to calculate the most consistent particle size distribution of the pattern.

As a commercially available device, a particle size measuring device (LS230, LS200, L
S100, manufactured by Coulter Co., Ltd.), laser diffraction particle size distribution analyzer (SALD2000, SALD2000A, S
ALD3000, manufactured by Shimadzu Corporation) Laser diffraction / scattering type particle size distribution analyzer (LA910, LA700, LA5)
00, manufactured by Horiba and Microtrack SP
A, Microtrack FRA, manufactured by Nikkiso Co., Ltd.).

(Method for Measuring Aspect Ratio) The aspect ratio (Z) is a ratio obtained from the relationship of Z = L / a. Here, L is the particle diameter (volume-based median diameter) of the inorganic layered compound in the dispersion obtained by the particle diameter measurement method by the diffraction / scattering method described above, and a is the cleaved unit shown in FIG. This is the unit thickness of the crystal layer 31. The “unit thickness a” is a value determined based on a result of independently measuring the thickness of the unit crystal layer in the inorganic layered compound by a powder X-ray analysis method described later or the like.

More specifically, as schematically shown in a graph of FIG. 4 in which the horizontal axis represents 2θ and the vertical axis represents the intensity of the X-ray diffraction peak, the lowest angle side of the observed diffraction peaks is shown. From the angle θ corresponding to the peak, the Bragg equation (nλ = 2Dsi
The interval determined based on nθ, n = 1, 2, 3,... is defined as “unit thickness a” (for details of the powder X-ray analysis method, for example, see “ Guide (a) ”, page 69 (1985) published by Kagaku Dojinsha).

When the resin composition corresponding to the resin composition layer 3 obtained by removing the dispersion medium from the dispersion liquid is subjected to powder X-ray analysis, usually, each of the inorganic layered compounds dispersed in the resin composition is removed. The surface distance can be obtained as the surface distance d shown in FIG.

More specifically, as shown in the graph of FIG. 5 in which the horizontal axis indicates 2θ and the vertical axis indicates the intensity of the X-ray diffraction peak, the diffraction corresponding to the above “unit thickness a” is shown. Of the diffraction peaks observed at a lower angle (larger interval) than the peak position, the interval corresponding to the peak at the lowest angle is defined as “plane interval d” (a <d).

As schematically shown in the graph of FIG. 6, when it is difficult to detect the peak corresponding to the above-mentioned "surface distance d" by overlapping with the halo (or background), the lower angle side than 2θd is detected. The area of the portion excluding the baseline is set as the peak corresponding to the “surface distance d”.
Here, “θd” is a diffraction angle corresponding to “(unit thickness a) + (width of single resin chain)”. (For details of the method of calculating the surface distance d, see, for example, Shuichi Iwata et al. Ed., "Encyclopedia of Clay", p. 35 and below and p. 271 and below, 1985,
(See Asakura Shoten Co., Ltd.)

Normally, the difference between the above-mentioned surface distance d and “unit thickness a”, that is, the value of k = (da) (when converted to “length”) constitutes the resin composition. It is equal to or greater than the width of a single resin chain [k = (da) ≧ width of a single resin chain]. Such “the width of a single resin chain” can be obtained by simulation calculation or the like (for example, “Introduction to Polymer Chemistry”, pp. 103-110, 198).
One year, see Doujin Kagaku) and polyvinyl alcohol (hereinafter abbreviated as PVA) in the case of 4 to 5 angstroms (2 to 3 angstroms of water molecules).

It is extremely difficult to directly measure the "true aspect ratio" of the unit crystal layer 31 in the resin composition layer 3. Although the above aspect ratio Z = L / a is not always equal to the “true aspect ratio” of the unit crystal layer 31 in the resin composition layer 3, the aspect ratio Z is “ It is valid to approximate the "true aspect ratio".

There is a relationship of a <d between the plane distance d obtained by powder X-ray analysis of the resin composition and the “unit thickness a” obtained by powder X-ray analysis of the inorganic layered compound alone. And the value of (da) is the value of resin 1 in the composition.
If the width of the main chain or more, in the resin composition,
The resin is inserted between the layers of each inorganic layered compound. Therefore, the unit crystal layer 31 in the resin composition layer 3
Is approximated by the above “unit thickness a”, that is, the “true aspect ratio” of the unit crystal layer 31 in the resin composition layer 3 is referred to as the “aspect ratio” in the dispersion of the inorganic layered compound. Approximating with "Z" is of sufficient relevance.

As described above, it is extremely difficult to measure the true grain size of the unit crystal layer 31 in the resin composition layer 3, but the unit crystal layer 31 in the resin 32 of the resin composition layer 3 is extremely difficult.
The particle size of the dispersion in the dispersion (resin / inorganic layered compound / dispersion medium)
Can be considered to correspond to the particle size L of the unit crystal layer in the inorganic layer compound.

However, the particle diameter L in the dispersion obtained by the diffraction / scattering method is considered to be very unlikely to exceed the major axis Lmax of the inorganic layered compound, so that the true aspect ratio (Lmax / a) is low. The possibility that the ratio is lower than the “aspect ratio Z” used in the present invention (Lmax / a <Z) is theoretically considerably low.

From the above two points, it is considered that the definition Z of the aspect ratio used in the present invention has sufficient validity. In the present specification, “aspect ratio” or “particle size” means “aspect ratio Z” defined above or “particle size L determined by a diffraction / scattering method”.

From the viewpoint of easily giving a large aspect ratio, an inorganic layered compound having a property of swelling and cleaving in a dispersion medium is preferably used.

The degree of "swelling / cleaving" of the inorganic layered compound used in the present invention to the dispersion medium can be evaluated by the following "swelling / cleaving" test. The swellability of the inorganic layered compound is preferably about 5 or more (more preferably, about 20 or more) in a swelling test described below. On the other hand, the cleavage property of the inorganic layered compound is preferably about 5 or more (and more preferably about 20 or more) in the cleavage test. In these cases, a liquid having a density smaller than the density of the inorganic layered compound is used as the dispersion medium. When the inorganic layered compound is a natural swellable clay mineral, it is preferable to use water as the dispersion medium.

<Swelling Test> 100 mL of the dispersion medium was placed in a 100 mL graduated cylinder, and 2 g of the inorganic layered compound was added thereto.
Add slowly. After standing, the volume (mL) of the inorganic layered compound dispersed layer is read as the swelling value from the scale at the interface between the inorganic layered compound dispersed layer and the supernatant after 24 hours at 23 ° C. The larger the value, the higher the swelling property.

<Cleaving test> 30 g of an inorganic layered compound was slowly added to 1500 mL of a dispersion medium, and a dispersion machine [Despa MH-L, manufactured by Asada Tekko Co., Ltd., blade diameter 52 mm, rotation speed 3]
100 rpm, container capacity 3 L, distance 28 between bottom and blade
mm] at a peripheral speed of 8.5 m / sec for 90 minutes (23 ° C.), take 100 mL of the dispersion liquid, put it in a graduated cylinder and let stand for 60 minutes, and then, from the interface with the supernatant, the volume of the inorganic layered compound dispersed layer Read (mL) as cleavage value.

As the inorganic layered compound which swells and cleaves in the dispersion medium, a clay mineral which swells and cleaves in the dispersion medium is particularly preferably used. Such clay minerals are generally
A type having a two-layer structure having an octahedral layer having aluminum or magnesium as a central metal on the upper surface of a tetrahedral layer of silica, and an octahedral layer having a tetrahedral layer of silica having aluminum or magnesium as a central metal. Is classified into a type having a three-layer structure in which is narrowed from both sides. The former two-layer structure type includes kaolinite group and antigolite group, and the latter three-layer structure type includes smectite group, vermiculite group and mica group depending on the number of interlayer cations. Can be.

As these clay minerals, more specifically, kaolinite, dickite, nacrite, halloysite, antigolite, chrysotile, pyrophyllite, montmorillonite, beidellite, nontronite, saponite, sauconite, stevensite, hectite Light, tetrasilyl mica, sodium teniolite, muscovite, margarite, talc, vermiculite, phlogopite, zansophyllite, chlorite and the like can be mentioned.

A clay mineral treated with an organic substance (hereinafter sometimes referred to as an organically modified clay mineral) can also be used as an inorganic layered compound (a clay mineral treated with an organic substance is described in Asakura Shoten, See Clay Encyclopedia).

Among the above clay minerals, smectites, vermiculites and micas are preferred from the viewpoint of swelling or cleavage, more preferably smectites. Examples of the smectite group include montmorillonite, beidellite, nontronite, saponite, sauconite, stevensite, and hectorite.

The dispersion medium for swelling or cleaving the inorganic layered compound is, for example, in the case of a natural swelling clay mineral, water, alcohols such as methanol, ethanol, propanol, isopropanol, ethylene glycol and diethylene glycol, dimethylformamide, dimethylsulfoxide, Acetone and the like are mentioned, and alcohols such as water and methanol are more preferable.

In the case of organically modified clay minerals, aromatic hydrocarbons such as benzene, toluene and xylene; ethers such as ethyl ether and tetrahydrofuran; ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone; n-pentane; aliphatic hydrocarbons such as n-hexane and n-octane, chlorobenzene, carbon tetrachloride,
Chloroform, dichloromethane, 1,2-dichloroethane,
Examples include halogenated hydrocarbons such as perchlorethylene, ethyl acetate, methyl methacrylate (MMA), dioctyl phthalate (DOP), dimethylformamide, dimethyl sulfoxide, methyl cellosolve, and silicone oil.

In the resin composition layer 3 of the present invention, the aforementioned high hydrogen bonding resin having a high content of a hydrogen bonding group or an ionic group is desirably used as the resin. The high hydrogen bonding resin is a content of a hydrogen bonding group or an ionic group in the high hydrogen bonding resin (when both are contained,
(Total amount of both) is 20 to 60 mol%, preferably 30 to 50 mol%. The content of these hydrogen bonding groups and ionic groups can be measured, for example, by a nuclear magnetic resonance (NMR) technique (1H-NMR, 13C-NMR, etc.).

The above-mentioned hydrogen bonding group includes a hydroxyl group, an amino group, a thiol group, a carboxyl group, a sulfonic acid group,
Examples of the ionic group include a carboxylate group, a sulfonate ion group, a phosphate ion group, an ammonium group, and a phosphonium group. Among the hydrogen bonding groups or ionic groups, more preferred are a hydroxyl group, an amino group, a carboxyl group, a sulfonic acid group, a carboxylate group, a sulfonic acid ionic group, an ammonium group and the like.

Specific examples of the high hydrogen bonding resin include, for example, PVA, ethylene-vinyl alcohol copolymer having a vinyl alcohol fraction of 40 mol% or more, polysaccharides, polyacrylic acid and its esters, and polyacrylic acid. Sodium, polybenzenesulfonic acid, sodium polybenzenesulfonate, polyethyleneimine, polyallylamine and its quaternary ammonium salt, polyvinyl thiol,
And polyglycerin. Among the above-mentioned resins, more preferable ones include PVA, polysaccharide, and ethylene-vinyl alcohol copolymer.

Here, PVA is a polymer obtained by, for example, hydrolyzing or transesterifying (saponifying) an acetic ester portion of a vinyl acetate polymer (that is, a polymer obtained as a copolymer of vinyl alcohol and vinyl acetate). )
Polymers obtained by saponifying trifluorovinyl acetate polymer, vinyl formate polymer, vinyl pivalate polymer, t-butyl vinyl ether polymer, trimethylsilyl vinyl ether polymer and the like (for details of PVA, for example, Povar Association, "PVA World", 1
992, Polymer Publishing Association; Nagano et al., "Poval"
1981, see Polymer Publishing Association).

The degree of “saponification” in PVA is preferably 70% or more in terms of mole percentage, more preferably 85% or more, and particularly preferably 98% or more, a so-called fully saponified product. The degree of polymerization in PVA is 100
It is preferably from 5000 to 5,000, more preferably from 200 to 3,000. Further, the PVA referred to in the present invention may be modified with a small amount of a copolymer monomer as long as the object of the present invention is not hindered.

Polysaccharides are biopolymers synthesized in a biological system by polycondensation of various monosaccharides, and here also include those chemically modified based on them. Examples include cellulose and cellulose derivatives such as hydroxymethylcellulose, hydroxyethylcellulose and carboxymethylcellulose, amylose, amylopectin, pullulan, curdlan, xanthan, chitin, chitosan and the like.

Further, the ethylene-vinyl alcohol copolymer (hereinafter referred to as EVOH) means that the vinyl alcohol content is 40 mol% or more and 80 mol% or less, and more preferably 45 mol% to 75 mol%. It means a certain EVOH. In addition, the melt index of EVOH (temperature 190
The value measured under the conditions of ° C and a load of 2160 g; hereinafter, referred to as MI) is not particularly limited, but is 0.1 to 50 g / 10 minutes. Further, the EVOH referred to in the present invention may be modified with a small amount of a comonomer as long as the object of the present invention is not hindered.

The above-mentioned modified polyvinyl alcohol and ethylene-vinyl alcohol copolymer refers to other unsaturated monomers copolymerizable with a vinyl acetate monomer in a vinyl ester resin during the production of polyvinyl alcohol, for example, Olefins such as ethylene, propylene, α-hexene and α-octene; unsaturated acids such as (meth) acrylic acid, crotonic acid, (anhydride) maleic acid, fumaric acid and itaconic acid, and alkyl esters and alkalis thereof. Salts, vinyl sulfonic acid, styrene sulfonic acid, 2-
Sulfonic acid-containing monomers such as acrylamide-2-methylpropanesulfonic acid and alkali salts thereof, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, and trimethyl-2-(-
1- (meth) acrylamide-1,1-dimethylethyl) ammonium chloride, trimethyl-3- (1-
(Meth) acrylamidopropyl) ammonium chloride, 1-vinyl-2-ethylimidazole and other quaternizable cationic monomers, styrene, alkyl vinyl ether, vinyl versatate, (meth) acrylamide and others.

The ratio of these copolymer components is not particularly limited, but is 5 to 5 units of vinyl alcohol.
0 mol% or less, preferably 30 mol% or less is preferable, and various forms obtained by any method such as random copolymerization, block copolymerization, and graft copolymerization are used as the form of copolymerization. .

Among these copolymers, a block copolymer in which a polycarboxylic acid component is copolymerized with a polyvinyl alcohol component is particularly preferably used. In the case where the polycarboxylic acid component is polymethacrylic acid, Particularly preferred. Further, the block copolymer is particularly preferably an AB block copolymer in which a polyacrylic acid chain is extended at one end of a polyvinyl alcohol chain, and the polyvinyl alcohol block component (a) Weight ratio of acrylic acid block component (b) (a) /
(B) is preferably 50/50 to 95/5,
In the case of 60/40 to 90/10, particularly preferable gas barrier properties are completed, and the bonding characteristics with the base material layer are remarkably completed. Further, among other modified forms, one particularly preferred form is a silyl group-modified polyvinyl alcohol resin composed of a saponified vinyl ester polymer modified with at least one compound having a silyl group in the molecule. is there.

The method for obtaining a modified polymer having such a composition is not particularly limited, but a silyl group is added to a vinyl alcohol-based polymer such as polyvinyl alcohol or modified polyvinyl acetate obtained by a conventional method. Reacting a compound having a silyl group into the polymer, or activating the terminal of polyvinyl alcohol or a modified product thereof, and introducing an unsaturated monomer having a silyl group in the molecule to the terminal of the polymer. Various modification methods such as graft copolymerization of the unsaturated monomer to a vinyl alcohol polymer molecular chain, a copolymer comprising a vinyl ester monomer and an unsaturated monomer having a silyl group in the molecule. And saponifying it, or polymerizing a vinyl ester in the presence of a silyl group-containing mercaptan or the like and saponifying it. Introducing silyl groups into Runado end,
Various methods such as are effectively used.

As the modified polyvinyl alcohol-based resin obtained by such various methods, any resin may be used as long as it has a silyl group in the molecule, and the silyl group contained in the molecule is an alkoxyl group or a silyl group. Those having a reactive substituent such as an acyloxyl group and a hydrolyzate of a silanol group or a salt thereof are preferable, and among them, a silanol group is particularly preferable.

Compounds having a silyl group in the molecule used for obtaining these modified polyvinyl alcohol resins include trimethylchlorosilane, dimethylchlorosilane, methyltrichlorosilane, vinyltrichlorosilane, diphenyldichlorosilane and triethylfluorosilane. Organohalosilanes such as silane, organosilicon esters such as trimethylacetoxysilane and dimethyldiacetoxysilane, organoalkoxysilanes such as trimethylmethoxysilane and dimethyldimethoxysilane,
Examples include organosilanols such as trimethylsilanol and diethylsilanediol, aminoalkylsilanes such as N-amiethyltrimethoxysilane, and organosilicon isocyanates such as trimethylsiliconisocyanate. The degree of modification by these silylating agents can be arbitrarily adjusted depending on the type, amount and reaction conditions of the silylating agent used.

The unsaturated monomer used in the method for saponifying a copolymer of a vinyl ester monomer and an unsaturated monomer having a silyl group in the molecule is vinyltrimethoxysilane. Many vinylsilane-based compounds such as vinylalkoxysilane and vinylmethyldimethoxysilane represented by vinyltriethoxysilane, and alkyl- or allyl-substituted vinylalkoxysilane represented by vinyltriisopropoxysilane; Further, polyalkylene glycol-modified vinyl silanes in which a part or all of these alkoxy groups are substituted with a polyalkylene glycol such as polyethylene glycol can be given. Furthermore, 3- (meth) acrylamino-propyltrimethoxysilane, 3
(Meth) acrylamide-alkylsilane represented by-(meth) acrylamide-propyltriethoxysilane and the like can also be preferably used.

On the other hand, a method of polymerizing a vinyl ester in the presence of a mercaptan having a silyl group and then saponifying the silyl group to introduce a silyl group into the terminal includes alkoxysilylalkyl such as 3- (trimethoxysilyl) -propylmercaptan. Mercaptan is preferably used.

The suitable range varies depending on the degree of modification of the modified polyvinyl alcohol-based resin of the present invention, that is, the content of the silyl group, the degree of saponification, etc., but it is important for the gas barrier property which is the object of the present invention. It becomes a factor. The content of the silyl group is usually 30 mol% or less, preferably 10 mol% or less, more preferably 5 mol% or less, as a monomer containing a silyl group, based on the vinyl alcohol unit in the polymer. And 2 mol% or less is particularly preferably used. Although the lower limit is not particularly limited, the effect is particularly remarkably exhibited when it is 0.1 mol% or more.

The above silylation rate indicates the ratio of the introduced silyl group after the silylation to the amount of the hydroxyl group contained in the polyvinyl alcohol resin before the silylation.

The modified polyvinyl alcohol-based resin into which the silyl group has been introduced is alcohol or alcohol /
By heating and dissolving with a mixed solvent of water, the compound is dissolved in an alcohol solvent due to the presence of the introduced silyl group.
The modified polyvinyl alcohol-based resin dissolved in the solvent, on the other hand, partially crosslinks by reacting by a dealcoholization reaction and a dehydration reaction. In the above reaction, the presence of water is essential, and it is preferable to use a mixed solvent of alcohol / water.

These various polyvinyl alcohol-based resins may of course be used alone. However, as long as the object of the present invention is not impaired, they may be used as copolymers with other copolymerizable monomers or mixed with other monomers. It can be used in combination with other possible resin compounds. Examples of such a resin include polyacrylic acid or esters thereof, polyester resin, polyurethane resin, polyamide resin, epoxy resin, melamine resin, and others.

The coating liquid used in the present invention is a liquid obtained by dispersing or dissolving the above-mentioned inorganic layer compound and resin in a dispersion medium. From the viewpoint of the gas barrier properties of the obtained laminated paper for liquid packaging, the dispersion medium is preferably a liquid that swells or cleaves the above-mentioned inorganic layered compound.

The composition ratio of the inorganic layered compound and the resin in the coating liquid is not particularly limited, but generally, the weight ratio of the inorganic layered compound to the resin (inorganic layered compound / resin).
But 1/100 to 100/1, and more preferably 1/20 to 10
/ 1 is preferred. The higher the weight ratio of the inorganic layered compound is, the more excellent the gas barrier property is, but in consideration of the bending resistance, the range of 1/20 to 2/1 is more preferable. In addition, the concentration of the inorganic layered compound and the resin in the coating solution,
The total of both is 0.1 to 70% by weight, from the viewpoint of productivity 1 to 15% by weight, more preferably 4 to 10% by weight.

The resin used for the resin composition layer 3 of the present invention is
When the resin is a high hydrogen bonding resin, a crosslinking agent for a hydrogen bonding group can be used for the purpose of improving the water resistance of the resin composition layer 3.

Preferable examples of the crosslinking agent include coupling agents such as titanium coupling agents, silane coupling agents, melamine coupling agents, epoxy coupling agents, isocyanate coupling agents, and the like. Epoxy compounds, copper compounds, zirconium compounds, organometallic compounds and the like can be mentioned. From the viewpoint of improving water resistance, organometallic compounds, zirconium compounds, water-soluble epoxy compounds, silane coupling agents are more preferably used,
More preferably, it is an organic metal compound such as an organic titanium compound.

Specific examples of the above-mentioned zirconium compounds include, for example, zirconium halides such as zirconium oxychloride, zirconium hydroxychloride, zirconium tetrachloride and zirconium bromide; and mineral acids such as zirconium sulfate, basic zirconium sulfate and zirconium nitrate. Zirconium salts of organic acids such as zirconium formate, zirconium acetate, zirconium propionate, zirconium caprylate and zirconium stearate;
Examples include zirconium complex salts such as ammonium zirconium carbonate, sodium zirconium sulfate, ammonium zirconium acetate, sodium zirconium oxalate, sodium zirconium citrate, and zirconium ammonium citrate.

Specific examples of the water-soluble epoxy compound include sorbitol polyglycidyl ether, sorbitan polyglycidyl ether, glycidyl ether epoxy resin, heterocyclic epoxy resin, glycidylamine epoxy resin, and aliphatic epoxy resin. I can give it.

Examples of the silane coupling agent include amino silane coupling agents, vinyl or methacryloxy silane coupling agents, epoxy silane coupling agents, methyl silane coupling agents,
Chloro silane coupling agents and mercapto silane coupling agent systems are exemplified.

Preferable examples of the crosslinking agent for a hydrogen-bonding group include a reaction for forming a cross-linked structure by reacting with a plurality of functional groups of a high hydrogen-bonding resin, that is, an organic metal compound capable of a cross-linking reaction. For example, the above-mentioned organometallic compounds which react with a plurality of hydroxyl groups of polyvinyl alcohol and form a cross-linking by a coordination bond or an ionic bond between a metal atom of the organometallic compound and an oxygen atom of the hydroxyl group are preferable.

The above-mentioned organometallic compounds capable of undergoing a crosslinking reaction are:
Higher crosslinking reactivity and higher crosslinking efficiency than inorganic metal salts. However, if the cross-linking reactivity is too high, the cross-linking reaction proceeds in the coating solution and coating (coating) becomes impossible, but the cross-linking reactivity of the organometallic compound can be changed by appropriately changing the ligand. Easy to control. The organic metal compound is also superior to the inorganic metal salt in that it has the advantage that the reactivity is easily controlled. Among the organometallic compounds, an organometallic compound having a chelating ligand such as acetylacetonate has an appropriate crosslinking reactivity and is preferable as a crosslinking agent for a hydrogen bonding group.

Preferred examples of such organometallic compounds include organic titanium compounds, organic zirconium compounds, organic aluminum compounds and organic silicon compounds.

Specific examples of the organic titanium compound include titanium orthoesters such as tetra-n-butyl titanate, tetraisopropyl titanate, butyl titanate dimer, tetra (2-ethylhexyl) titanate and tetramethyl titanate; titanium acetylacetonate;
Titanium chelates such as titanium tetraacetylacetonate, polytitanium acetylacetonate, titanium octylene glycolate, titanium lactate, titanium triethanolamine, titanium ethyl acetoacetate, and titanium acylates such as polyhydroxytitanium stearate. No.

Specific examples of the organic zirconium compound include zirconium normal propylate, zirconium normal butyrate, zirconium tetraacetylacetonate, zirconium monoacetylacetonate, zirconium bisacetylacetonate, zirconium acetylacetonate bisethylacetoacetate and the like. No.

Specific examples of the organoaluminum compound include aluminum acetylacetonate, aluminum organic acid chelate and the like. Examples of the organic silicon compound include a silicon compound having a ligand included in the compounds exemplified as the organic titanium compound or the organic zirconium compound.

Among these, a chelate compound is preferred in terms of stability in a coating solution. In terms of the stability of the coating solution, the stability is greatly improved by setting the coating solution to be acidic. The above acidic conditions include a pH of 5
Or less, more preferably pH 3 or less. There is no particular lower limit on the pH of the coating solution, but usually the pH is 0.1.
5 or more. As the addition method, it is preferable to dilute with an alcohol and add. By including the mixing step of the above resin and a crosslinking agent, the resin composition layer 3 in which the above resin is crosslinked can be obtained.

The amount of the crosslinking agent to be added is not particularly limited, but the ratio K (K = CN / HN) of the number of moles of the crosslinking group (CN) of the crosslinking agent to the number of moles of the hydrogen bonding group (HN) of the resin is used. But,
It is preferable to use it in the range of 0.001 or more and 10 or less. More preferably, the molar ratio K is in the range of 0.01 or more and 1 or less.

The method of blending or producing the resin composition comprising the above-mentioned inorganic layered compound and resin is not particularly limited.
From the viewpoint of uniformity or ease of operation during compounding, for example,
A method in which a liquid in which a resin is dissolved in a solvent and a dispersion in which the inorganic layered compound has been swollen and cleaved in advance with a dispersion medium are mixed, and then the solvent and the dispersion medium are removed (method 1). The inorganic layered compound is swollen with the dispersion medium A method of mixing the cleaved dispersion liquid with a resin, dissolving the resin in a dispersion medium, and then removing the dispersion medium (method 2), adding an inorganic layered compound to a liquid in which the resin is dissolved in a solvent. A method of swelling and cleaving the inorganic layered compound using the solvent as a dispersion medium to form a dispersion and removing the solvent (method 3), or a method of hot-kneading the resin and the inorganic layered compound (method 4) can be used. It is. From the point that a large aspect ratio of the inorganic layered compound can be easily obtained,
The former three methods are preferably used. In the former three cases, it is preferable to perform treatment using a high-pressure dispersion device from the viewpoint of dispersibility of the inorganic layered compound.

As a high-pressure dispersion device, for example, Microfluid
There is an ultrahigh-pressure homogenizer (trade name: Microfluidizer) manufactured by ics Corporation or a Nanomizer manufactured by Nanomizer, and a homogenizer manufactured by Manton-Gaulin, such as a homogenizer manufactured by Izumi Food Machinery.

In the above three methods, after the solvent and the dispersion medium are removed from the system, the obtained laminated paper for liquid packaging is
Heat aging at 110 ° C. or more and 220 ° C. or less
In particular, the water resistance (meaning of gas barrier properties after a water resistance environment test) of the laminated paper for liquid packaging can be improved, which is preferable. The aging treatment is particularly effective when the resin is a high hydrogen bonding resin.

The aging time is not limited, but the laminated paper for liquid packaging needs to reach at least the set temperature,
For example, in the case of a method using a heat medium such as a hot air dryer,
It is preferably from 1 second to 100 minutes. There is no particular limitation on the heat source, and various methods such as heat roll contact, heat medium contact (air, oil, etc.), infrared heating, microwave heating, and the like can be applied.

As shown in FIG. 9, the high-pressure dispersion treatment in the present invention is to pass a composition mixture obtained by mixing particles to be dispersed or a dispersion medium, etc., through a plurality of thin tubes 11 at high speed to collide with each other. To perform dispersion treatment under special conditions such as high shear and high pressure.

In such a high-pressure dispersion treatment, the composition mixture is preferably passed through a thin tube 11 having a diameter of 1 μm to 1000 μm. It is preferable that a pressure of 100 kgf / cm ² or more is applied.
/ Cm ² or more, more preferably 1000
kgf / cm ² or more. Further, when the composition mixture passes through the narrow tube 11, it is preferable that the maximum arrival speed of the composition mixture reach 100 m / s or more, and the heat transfer speed is 100 kcal / hr or more.

The principle of the high-pressure treatment in the high-pressure dispersion treatment apparatus used for the high-pressure dispersion treatment will be described schematically.
The composition mixture is sucked into the feeder tube 13 having a larger diameter than the thin tube 11 by the pump 12 and taken in. Subsequently, a high pressure is applied to the composition mixture in the feeder tube 13 by the pump 12. At this time,
Check valve provided on feeder tube 13 (not shown)
As a result, the composition mixture in the feeder tube 13 is
Extruded toward one. Therefore, the composition mixture is in a high-pressure and high-speed state in the thin tube 11,
Each of the inorganic layered compound particles of the composition mixture collides with each other and the inner wall of the thin tube 11, and the diameter and thickness, particularly the thickness, of each of the inorganic layered compound particles are finely divided and more uniformly dispersed. Then, it is taken out of the discharge pipe 14 to the outside.

For example, in the case where the flow velocity at the point where the maximum velocity is instantaneously reached with respect to the composition mixture which is the sample to be processed in the thin tube 11 is 300 m / s, the volume is 1 × 10 ^−3.
passes through a cube of m ³ at 1 / (3 × 10 ⁵ ) sec,
When the temperature of the composition mixture increases by 35 ° C., energy is transferred to the composition mixture by pressure loss. The heat transfer rate is such that the specific gravity of the composition mixture is 1 g / cm ^{3 and the} specific heat 1 cal /
At g ° C., it is 3.8 × 10 ⁴ kcal / hr.

[0098] The stretched film layer 2 of the present invention is not particularly limited, but is preferably at least one selected from the group consisting of biaxially stretched polyamide, biaxially stretched polyethylene terephthalate, and biaxially stretched polypropylene.

The stretched film layer 2 preferably has a higher tensile strength, and has an elongation at break of 70%.
0% or less is desirable, and further preferably 500% or less.
As the polyamide-based biaxially stretched film, nylon-
6, nylon-6,6, metaxylenediamine-adipic acid condensation polymer, and the like.

In laminating the resin composition layer 3 of the present invention on another layer, for example, the paper-like layer 1, each surface between them is subjected to corona treatment, flame plasma treatment, ozone treatment, electron beam irradiation treatment. , An anchor process may be performed. When performing the anchor treatment, as the material of the anchor layer, for example, polyethyleneimine-based, alkyl titanate-based,
Polybutadiene type, urethane type and the like are not particularly limited,
From the viewpoint of water resistance, an anchor layer made of a urethane-based compound prepared from an isocyanate compound and an active hydrogen compound is preferable.

The isocyanate compounds include tolylene diisocyanate (TDI), 4,4'-diphenylmethane diisocyanate (MDI), xylylene diisocyanate (XDI), and hexamethylene diisocyanate (HDI).
I), 4,4'-methylenebiscyclohexyl isocyanate (H12MDI), isophorone diisocyanate (IP
DI).

The active hydrogen compound may be any compound having a functional group capable of binding to an isocyanate compound.
For example, ethylene glycol, diethylene glycol,
Low molecular weight polyols such as dipropylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, trimethylolpropane, polyethylene glycol, polyoxypropylene glycol, ethylene oxide / propylene oxide copolymer, polytetramethylene Examples include polyether polyols such as ether glycol, poly-β-methyl-δ-valerolactone, polycaprolactone, and polyester polyols such as polyester from diol / dibasic acid.

In the active hydrogen compound, a low molecular weight polyol is particularly preferable, and a diol in the low molecular weight polyol is more preferable. Here, diols are ethylene glycol, diethylene glycol, dipropylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, etc., and the dibasic acids are adipic acid, azelaic acid, sebacic acid, and isophthalic acid. And terephthalic acid. Other polyols include active hydrogen compounds such as castor oil, liquid polybutadiene, epoxy resin, polycarbonate diol, acrylic polyol, and neoprene. The mixing ratio between the isocyanate compound and the active hydrogen compound is not particularly limited, but isocyanate groups and active hydrogen groups, for example, -OH, -NH,
It is preferable to determine the amount of addition in consideration of the equivalence relationship with —COOH. For example, the number of moles of isocyanate groups (A
N) and the number of moles (BN) of active hydrogen groups of the active hydrogen compound, R (R = AN / BN), are 0. 0 from the viewpoint of adhesive strength.
001 or more is preferable, and 10 or less is preferable from a viewpoint of adhesiveness and blocking. The molar ratio R is 0.01
More preferably, it is within the range of 1 or less. Each mole number of the isocyanate group and the active hydrogen group is 1H-N
It can be quantified by MR and 13 C-NMR.

The method of laminating the anchor layer on the resin composition layer 3 or another layer, for example, the paper-like material layer 1 is not particularly limited, but an anchor coating agent containing an isocyanate compound and an active hydrogen compound is dissolved in a solvent. Then, a coating method using an anchor coating agent solution is preferable.

Specific examples of the coating method include a roll coating method such as a direct gravure method, a reverse gravure method, a microgravure method, a two-roll beat coating method, a bottom feed three-reverse coating method, and a doctor knife method. Examples of the method include a die coating method, a dip coating method, a bar coating method, and a coating method combining these methods.

The solvent component in the anchor coating agent solution is mainly an organic solvent, and includes alcohols, aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, esters, ketones, ethers, and the like. Halogenated hydrocarbons and mixed solvents thereof are exemplified.

The coating thickness obtained by applying the anchor coating agent solution in a film form is not particularly limited, but the dry thickness is 0.01 μm
It is preferable that the distance is set to be about 5 μm. The larger the coating thickness, the better the heat sealing strength, but the lower the gelboflex resistance. Therefore, the coating thickness is more preferably from 0.03 μm to 2.0 μm, and still more preferably from 0.05 μm to 1.0 μm.

The thickness of the resin composition layer 3 of the present invention is preferably in the range of 1 nm to 10 μm in dry thickness, more preferably 10 nm.
nm to 5 μm, more preferably 0.1 μm
２2 μm. When the thickness exceeds 10 μm, the flexibility of the obtained laminated paper for liquid packaging deteriorates. If the thickness is less than 1 nm, an effective gas barrier property cannot be obtained.

In the laminated paper for liquid packaging of the present invention, when an anchor layer, in particular, a urethane-based anchor layer is used, the resin composition layer 3 contains a surfactant for improving the adhesion to the anchor layer. It is desirable to include one. The surfactant is not particularly limited as long as it can improve the adhesiveness and adhesiveness between the anchor layer and the resin composition layer 3, and examples thereof include an anionic surfactant and a cationic surfactant. , Zwitterionic surfactants and non-ionic surfactants.

Examples of the anionic surfactant include carboxylic acid types such as aliphatic monocarboxylates, N-acyloylglutamate, alkylbenzene sulfonates, naphthalene sulfonate-formaldehyde condensates, and dialkyl sulfosuccinates. Sulfonate type such as sulfonic acid type, alkyl sulfate salt, alkyl sulfate polyoxyethylene salt, etc., phosphate type such as alkyl phosphate salt, borate type such as alkyl borate salt, etc. Surfactants, fluorine-based anionic surfactants such as sodium perfluorodecanoate and sodium perfluorooctylsulfonate, and silicone-based anions having an anionic group such as a polymer having a polydimethylsiloxane group and a metal carboxylate. Surfactants.

Examples of the cationic surfactant include, for example,
Amine salt types such as alkylamine salts, alkyltrimethylammonium salts, dialkyldimethylammonium salts,
A quaternary ammonium salt type such as an alkyldimethylbenzylammonium salt is exemplified.

Examples of the zwitterionic surfactant include carboxybetaine type such as N, N-dimethyl-N-alkylaminoacetic acid betaine and glycine such as 1-alkyl-1-hydroxyethyl-1-carboxymethylimidazolinium betaine. Type.

Examples of the nonionic surfactant include ester types such as glycerin fatty acid ester, sorbitan fatty acid ester and sucrose fatty acid ester, polycondensates of polydimethylsiloxane group and alkylene oxide adduct, polysiloxane-polyoxyalkylene. Ether type such as copolymer, polyoxyethylene alkylphenyl ether, polyoxyethylene alkyl ether, polyoxyethylene polyoxypropylene block polymer, etc., ester ether type such as polyethylene glycol fatty acid ester, polyoxyethylene sorbitan fatty acid ester, etc., aliphatic alkanol Examples thereof include alkanolamide type such as amide and fluorine type such as diglycerin ester of perfluorodecanoic acid and perfluoroalkylalkylene oxide compound.

Among the above surfactants, in particular, those having 6 carbon atoms
An alkali metal salt of a carboxylic acid having an alkyl chain of not more than 24 or less, an ether type nonionic surfactant such as polydimethylsiloxane-polyoxyethylene copolymer (silicone nonionic surfactant), Fluorinated nonionic surfactants such as alkyl ethylene oxide compounds (fluorinated nonionic surfactants)
Is preferred.

When forming a gas barrier layer 3, for example, when a coating liquid is used, the amount of the surfactant is preferably 0.001 to 5% by weight in the coating liquid from the viewpoint of the effect.
0.003 to 0.5% by weight is more preferable, and 0.005 to 0.5% by weight.
-0.1% by weight is particularly preferred.

The container for liquid packaging of the present invention is formed by using the above-mentioned laminated paper for liquid packaging so as to package contents such as liquid. The thickness of the laminated paper for liquid packaging is not particularly limited, but is preferably 50 μm or more from the viewpoint of protection of the contents to be packaged, and is preferably 700 μm or less from the viewpoint of cost.

In the present invention, layers other than those described above may be provided as long as the effect is not impaired. Each material of the liquid packaging container may contain additives such as an ultraviolet absorber, a coloring agent, and an antioxidant. May be mixed.

The shape of the container body of the liquid packaging container of the present invention is not particularly limited. However, the shape of the container body is free-standing, for example, a carton shape, a BIB (bag-in-box) shape shown in FIG. And a container body 6 having a brick shape or a standing pouch shape shown in FIG.

Examples of the use of the laminated paper for liquid packaging and the container for liquid packaging of the present invention include juice, sake, confectionery, confectionery, miso, pickles, konjac, chikuwa, kamaboko, other processed marine products, tofu, pudding, meatballs Food packaging applications for foods containing water such as hamburgers, hams and sausages, pesticides,
Packaging applications in the medical, chemical, electronic, and mechanical fields, such as oxidizing liquid chemical packaging and oxidizing liquid chemical packaging, such as fertilizers, cosmetics, aromatics, and medical infusions.

[0120]

The present invention will be described below in detail with reference to examples, but the present invention is not limited to these examples. The methods for measuring various physical properties are described below.

[Thickness Measurement] The thickness of 0.5 μm or more was measured with a commercially available digital thickness gauge (contact type thickness gauge, trade name: ultra-high precision decimicro head MH-15M, manufactured by Nippon Kogaku Co., Ltd.). On the other hand, the thickness of less than 0.5 μm is determined by a gravimetric analysis method (the measured weight of a film having a certain area is divided by the area and further divided by the specific gravity of the composition) or the actual coating film thickness by the IR method. A calibration curve with IR absorption was prepared and determined from the calibration curve. Further, in the case of measuring the coating thickness of the resin composition of the present invention, for example, the elemental analysis method [the ratio of the specific inorganic element analysis value of the laminate (derived from the resin composition layer) to the specific element fraction of the inorganic layered compound alone] Method for determining the ratio between the resin composition layer of the present invention and the paper-like layer).

[Measurement of Particle Size] Using a laser diffraction / scattering type particle size distribution analyzer (LA910, manufactured by HORIBA, Ltd.), a volume-based median of particles considered to be an inorganic layered compound present in the resin matrix of the medium. The diameter was measured as a particle diameter L. The undiluted liquid dispersion was measured with an optical path length of 50 μm in a paste cell, and the dilute liquid of the dispersion was measured with an optical path length of 4 mm by a flow cell method.

[Calculation of Aspect Ratio] X-ray diffractometer (XD
-5A (manufactured by Shimadzu Corporation), the diffraction measurement of the inorganic layered compound alone and the resin composition by the powder method was performed. Thereby, the unit thickness a of the inorganic layered compound was determined, and further, from the diffraction measurement of the resin composition, it was confirmed that there was a portion where the plane interval of the inorganic layered compound was widened. Using the particle diameter L obtained by the above method, the aspect ratio Z was calculated by the equation of Z = L / a.

[Oxygen Permeability Measurement] Based on JIS K7126, an ultra-sensitive oxygen permeability measuring device (OX-TRAN)
ML, manufactured by MOCON Co.) at 23.7 ° C. (60% RH on the paper-like material layer side as the outer layer, and 100% RH on the thermoplastic resin layer side as the inner layer).

[Example 1] [Coating liquid for resin composition layer] Dispersion vessel [trade name: Despa MH]
-L, manufactured by Asada Tekko Co., Ltd.], add 1860 g of ion-exchanged water (specific electric conductivity 0.7 μS / cm or less), and further add P
VA [PVA117H; manufactured by Kuraray Co., Ltd., saponification degree: 99.
6%, degree of polymerization 1700] and stirring under low speed (150
The temperature was raised to 95 ° C. at 0 rpm at a peripheral speed of 4.10 m / min), stirred for 1 hour, and dissolved to obtain a solution (A).

Next, the solution (A) was stirred for 60 hours.
After lowering the temperature to 0 ° C., a solution obtained by adding 0.18 g of a nonionic surfactant (trade name: SH3746, manufactured by Dow Corning Toray Co., Ltd.) to a mixed solution of 125 g of 1-butanol and 375 g of isopropyl alcohol was added to the mixture. The above solution (A)
To obtain a mixture (B). The nonionic surfactant is a polydimethylsiloxane-polyoxyethylene copolymer.

1960 g of the mixture (B) was charged into a stirring emulsifying apparatus (trade name: vacuum emulsifying apparatus PVQ-3UN, manufactured by Mizuho Industry Co., Ltd.). 50 g of natural montmorillonite (Kunipia F; manufactured by Kunimine Kogyo Co., Ltd.) as powder so that the weight ratio of the resin to the inorganic layered compound is 2: 1.
After confirming that the montmorillonite was substantially precipitated in the solution, the mixture was stirred at 600 mmHg and 5000 rpm for 10 minutes to obtain a resin composition mixture (C).

A 2000 g of the resin composition mixture (C) was dispersed in a high-pressure dispersing apparatus (trade name: ultra-high pressure homogenizer M110-
E / H, manufactured by Microfluidics Corporation)
By treating once at 50 kgf / cm ² , a uniform dispersion (D) having good dispersibility was obtained. The solid content concentration of the dispersion (D) was 7.5% by weight.

A dispersion (D) composed of PVA and montmorillonite was cast into a film and subjected to X-ray analysis.
The interplanar spacing d of the swelled and cleaved montmorillonite (inorganic layered compound) was measured.

As a result of obtaining the plane distance d from the diffraction peak obtained from the X-ray analysis, the plane distance d was larger than the unit thickness a. Therefore, the montmorillonite was cleaved sufficiently for the above-mentioned reason. I found out. At this time, the aspect ratio of the cleaved inorganic layered compound is 45.
It was 0 or more.

The dispersion (D) was adjusted with hydrochloric acid so that the pH of the dispersion (D) was 3 or less under low-speed stirring (1500 rpm, peripheral speed 4.10 m / min). Titanium acetylacetonate [TC1
5.3, was gradually added to obtain a coating liquid for a resin composition layer.

[Laminated paper for liquid packaging] Basis weight 340 g / m ²
A 20 μm-thick biaxially oriented polypropylene (OPP) film (Pyren P2102: manufactured by Toyobo Co., Ltd.) having a surface corona-treated is laminated as a stretched film layer on the kraft paper, and an anchor coat is formed on the OPP film. Agent [Adcoat AD335 / CAT10 = 15/1
(Weight ratio: manufactured by Toyo Morton Co., Ltd.)] (test coater; manufactured by Yasui Seiki: microgravure coating method, coating speed 3 m / min, drying temperature 80 ° C.). The dry thickness of the anchor coat layer was 0.05 μm.

Next, the coating solution for the resin composition layer was subjected to gravure coating (test coater; manufactured by Yasui Seiki Co., Ltd .: microgravure coating method, coating speed: 3 m / min, drying temperature: 100 ° C.). Then, a coating film having a resin composition layer formed thereon based on the resin composition layer coating solution was obtained. The dry thickness of the resin composition layer was 0.5 μm.

Subsequently, an adhesive [Adcoat AD503 / CAT10 =
15/1 (weight ratio: manufactured by Toyo Morton Co., Ltd.), a 15 μm-thick biaxially stretched polyethylene terephthalate film [Espet T4100, manufactured by Toyobo Co., Ltd.], 50 μm thickness as a sealant layer Metallocene LL film [TUX-FCS, Tosero Co., Ltd.
Was dry-laminated on the surface on the biaxially stretched polyethylene terephthalate side, to obtain a laminated paper for liquid packaging.

The characteristics (oxygen permeability) of the laminated paper for liquid packaging were measured in accordance with the above-mentioned measuring methods.
The oxygen permeability of the laminated paper for liquid packaging is 0.1 (mL /
atm · m ² · day), and had excellent oxygen permeability and excellent gas barrier properties.

[0136]

As described above, the laminated paper for liquid packaging of the present invention has a paper-like material layer, a resin composition layer having an inorganic layered compound, and a thermoplastic resin layer.

Therefore, the above-mentioned structure is excellent in the protection property of the packaged object such as food contents such as gas barrier property by the inorganic layered compound, and the aluminum foil having the conventional film thickness is omitted by the inorganic layered compound. So you can
This has the effect of facilitating disposal processing.

The container for liquid packaging according to the present invention has a configuration in which a container body for packaging an article to be packaged is formed of the above-mentioned laminated paper for liquid packaging.

[0139] Therefore, the above-described configuration has an effect that the protection of food contents such as gas barrier properties is excellent, and the disposal process can be facilitated.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing an example of the laminated paper for liquid packaging of the present invention.

FIG. 2 is a schematic sectional view showing another example of the laminated paper for liquid packaging of the present invention.

FIG. 3 is a schematic sectional view showing a resin composition layer of the laminated paper for liquid packaging.

FIG. 4 is an X-ray diffraction graph of the inorganic layered compound for calculating the “unit thickness a” of the inorganic layered compound in the resin composition layer.

FIG. 5 is an X-ray diffraction graph of the inorganic layered compound for calculating the “plane spacing d” of the inorganic layered compound in the resin composition layer.

FIG. 6 calculates the “plane spacing d” of the inorganic layered compound when the peak corresponding to the “plane spacing d” in the graph of FIG. 5 overlaps with a halo (or background) and is difficult to detect. It is an X-ray diffraction graph at the time.

FIG. 7 is a schematic perspective view showing an example of the liquid packaging container of the present invention.

FIG. 8 is a schematic perspective view showing another example of the liquid packaging container of the present invention.

FIG. 9 is an explanatory view schematically showing a high-pressure dispersion process used in the production of the liquid packaging laminate paper.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Paper-like material layer 3 Resin composition layer 4 Thermoplastic resin layer

Claims (13)

[Claims] 1. A laminated paper for liquid packaging, comprising a paper-like material layer, a resin composition layer having an inorganic layered compound, and a thermoplastic resin layer. 2. The laminated paper for liquid packaging according to claim 1, further comprising a stretched film layer. 3. The method according to claim 1, wherein the thermoplastic resin layer is made of a polyolefin resin.
The laminated paper for liquid packaging according to the above. 4. The laminated paper for liquid packaging according to claim 1, further comprising a metal or metal oxide barrier layer. 5. The stretched film is made of a biaxially stretched polyamide,
3. The laminated paper for liquid packaging according to claim 2, wherein the laminated paper comprises at least one selected from the group consisting of axially stretched polyethylene terephthalate and biaxially stretched polypropylene. 6. The laminated paper for liquid packaging according to claim 1, wherein the inorganic layered compound has a property of expanding and cleaving in a dispersion medium. 7. The resin composition according to claim 1, wherein the resin composition layer is obtained by subjecting a mixed solution of a resin composition having an inorganic layered compound to a high-pressure dispersion treatment. The laminated paper for liquid packaging according to the above. 8. The laminated paper for liquid packaging according to claim 7, wherein the high-pressure dispersion treatment is carried out under a pressure condition of 100 kgf / cm ² or more. 9. An inorganic layered compound having an aspect ratio of 50 to 50.
The laminated paper for liquid packaging according to any one of claims 1 to 8, wherein the laminated paper is 5000. 10. An inorganic layered compound having an aspect ratio of 20.
9. The method according to claim 1, wherein the number is from 0 to 3000.
The laminated paper for liquid packaging according to any one of the above. 11. The resin composition layer contains a high hydrogen bonding resin, and the weight ratio of the inorganic layered compound to the high hydrogen bonding resin is as follows:
The laminated paper for liquid packaging according to any one of claims 1 to 10, wherein the thickness is in the range of (1/100) to (100/1). 12. The liquid packaging laminate according to claim 11, wherein the high hydrogen bonding resin is polyvinyl alcohol and a modified product thereof, a polysaccharide, or an ethylene-vinyl alcohol copolymer and a modified product thereof. paper. 13. A container body for packaging an article to be packaged,
A liquid packaging container formed of the laminated paper for liquid packaging according to any one of claims 1 to 12.